IXETJSOEIA. 219 



of a soft substance called "sorcode;" there is no distinction 

 of sexes, and generation takes place by sub-division, each 

 cell separating into two, and these again into two more, and 

 so on with marvellous rapidity ; this is the usual method of 

 increase, but occasionally an act of conjugation takes place, 

 two cells blending into one at the points of contact, the 

 result of which is a nucleus or cell within the original one. 

 These animated cells are of all forms, having prolongations 

 which appear to be thrown out to absorb any particle of 

 organic matter within reach, which then enters within the 

 soft substance of the animalcule and is digested or dissolved, 

 such are the Amboeba, the Actinophrys, &c. (see fig 1) ; a 

 step or two higher from these, the very lowest, infusoria are 

 found to possess the first rudiments of organs in the form 

 of cilia, which consist of minute elongations having a constant 

 vibratory motion, for the purpose of causing a current in the 

 water in which they live and bringing food into their 

 vicinity. 



Some very curious and complicated changes take place in 

 the lowest of the animals, very similar to those in the lowest 

 vegetables ; and what has been called the life-history of these 

 beings, often embraces a great number of forms before the 

 circle of their metamorphoses comes round to the starting- 

 point. Some of these phases of existence are quite different 

 from those going before and after them, and as the vegetable 

 free-cell at one time is capable of motion, it has long been 

 mistaken for an active living animalcule (the Protococcus 

 pluvialis, &c.), and there can be no doubt but that it will be 

 found that many of the lower forms of animated life 

 described by Ehrenberg and others, and still considered as 

 such, will prove to be merely different stages of the meta- 

 morphosis of the same protozoon ; or it may be not an 

 animal at all, but a simple vegetable or protophyte. 



Dr. Carpenter says, " It is quite certain that the Desmi- 

 diaceae, like the confervoid plants in general, grow at the 

 expense of the inorganic elements which surround them, 

 instead of depending upon other living beings for their sub- 

 sistence, and that they decompose carbonic acid and give off 

 oxygen under the influence of sunlight. They have the 



